View Full Version : Vibration after impact

07-31-2006, 08:10 PM
This weekend at the lake, I bumped something and immediately felt a vibration. I figured that I had dented/mangled the prop. It vibrated enough that I was not comfortable planing the boat, I idled back to the ramp. The vibration kicks in at about 1800 rpm. When the boat was on the trailer, I took a look at the prop. It looked almost normal, save a couple of very small dings. I started the engine and engaged the transmission, ran it up to 2500 rpm on the trailer with no vibration. That leads me to belive that it can't be the tranny or the shaft. My dealer tells me that it doesn't take much to cause a vibration. Anyone have any experience with this? This is my first direct drive ,all my experience (save a couple years with the Texas Aggie Waterski Team) is with outboards. Thanks ( sorry about the long thread)

07-31-2006, 08:20 PM
Past experience says dealer is right on. Have the prop fixed.

07-31-2006, 09:55 PM
Dahouse, welcome to the board. If you are in N Tx, it is easy to see how you may have caught your prop. The lakes are as bad as I have ever seen them. My bet is the prop. You can oder one on line and have yours re-worked for a back up. The joys of boating.

07-31-2006, 10:01 PM
Have the prop spin tested. As said above it doesn't take much at all to cause problems. I had my CNC prop tap a small twig, and I mean twig and the damage was a blade tip bent ever so slightly, to the point you had to stare at it for 5-10 minutes before noticing it. Had the prop redone and voila!
It takes ALOT to bend a shaft or the journal & strut. Doubt you did that from the sounds of your collision

east tx skier
07-31-2006, 10:19 PM
Welcome! Start with the prop. The smallest ding can really creat some uncomfortable vibrations. If that doesn't work, the shaft may be bent. Perhaps the strut, too. Just start working your way back.

I ran over a broken off, submerged channel marker two years ago. Mangled the prop, bent the shaft beyond repair, drove the prop into the hull, and knocked the engine out of alignment. And that's not the worst of it. It was my father-in-law's boat. Do a search for channel marker and you can find pictures. Not the end of the world though. All repairable. Just takes some time and $$$.

Welcome to inboard ownership.

07-31-2006, 11:46 PM
Thanks for the advice, prop's goin to the shop @ lunch Tuesday ( and I'm ordering a spare). For everything else there's mastercard, right?

07-31-2006, 11:49 PM
Definetly order a CNC prop and keep what you have as a backup after it is rebuilt. These props can vibrate with just the smallest ding, or you could hit something huge and somehow escape all damage.

Trust me, I've seen both sides of it:D